This invention relates to the use of existing mechanical locks with mechanical tumbler types of cylinders for electronic access control.
A number of access control systems have existed incorporating electrically operated locking devices with decision-making electronics for permitting access housed within the lock's trim, such as Touchcode system manufactured by Yale Electronics of Charlotte, N.C., Nova System manufactured by Kaba of Southington, Conn., and Solitaire System manufactured by Marlock of Chicago, Ill. Some of these access lock systems employ keypads, some cards, some purely electronic, magnetic or optic keys, and some employ mechanical keys equipped with electronic circuitry.
For the benefit of the current invention, distinction must be made between the purely electronic, magnetic or optical keys, mechanical keys, and mechanical keys equipped with electronic, magnetic or optical features.
A key comprised of purely electronic circuitry, magnetic or optical data storage and identification for access is an electronic key. In their use, the circuitry or recorded data is transferred to the reader means or reader recognizes the pattern held by the key optically. This key does not carry any mechanical cut configuration which is critical for granting access. These types of keys can be found in U.S. Pat. Nos. 3,797,936, Dimitriadis, granted Mar. 19, 1974; 4,209,782, Donath et al., granted Jun. 24, 1980; 4,257,030, Bruhin et al., granted Mar. 17, 1981; 4,620,088, Flies, granted Oct. 20, 1986; 4,659,915, Flies, granted Apr. 21, 1987; 4,789,859, Clarkson et al., granted Dec. 6, 1988. Mechanical keys are keys which activate a mechanical device through direct contact with the interpreting device, the tumblers. Based on the depth and placement configuration of the cut's meeting the tumblers and creating the proper alignment of such tumblers, access is granted. In most cases, once the proper alignment is established, the keyholder is able to turn the key to lock and unlock the locking device. However, in some cases, a push or pull action may be necessary for the locking and unlocking of the locking device. The aforementioned tumblers can be pin tumblers, lever tumblers, disk tumblers, rotary disk tumblers, or slider tumblers. Examples of mechanical keys may be found in U.S. Pat. Nos. 480,299, H. G. Voight, granted Aug. 9, 1892; 550,111, H. B. Sargent, granted Nov. 19, 1895; 564,029, H. B. Sargent, granted Jul. 14, 1896; 3,208,248, Tornoe, granted Feb. 6, 1963; 4,723,427, Oliver, granted Feb. 9, 1988; 4,732,022, Oliver, granted Mar. 22, 1988; 4,823,575, Florian et al., granted Apr. 25, 1989.
A mechanical key equipped with electronic circuitry, magnetic or optical data storage or optically recognizable features can be found in U.S. Pat. Nos. 3,733,862, Killmeyer, granted May 22, 1973; 4,144,523, Kaplit, granted Mar. 13, 1979; 4,326,124, Faude, granted Apr. 20, 1982; 4,562,712, Wolter, granted Jan. 7, 1986; 4,663,952, Gelhard, granted May 12, 1987; and 4,686,358, Seckinger et al., granted Aug. 11, 1987. See also Pat. Nos. 5,003,801, Stinar et al., 4,998,952, Hyatt et al., 5,131,038, Puhl et al., 5,140,317, Hyatt et al. and 5,245,329, Gokcebay. Keys shown in some of these patents carry the secondary element whether it is an electronic circuitry or some other type of coded data or recognizable pattern, in addition to its mechanically operating feature as described in purely mechanical keys. In some instances, both mechanical and no-nmechanical features of the key are used simultaneously for granting access and in some cases, these features are used independently. None of the patents discloses a key with built-in or built-on modular, self-contained, off-the-shelf memory cell formed in a can-like container as manufactured, for example, by Dallas Semiconductor.
The current invention relates to the conversion of mechanical lock cylinders and keys for electronic use without altering their mechanical functionality, as well as to a simple cylinder and a key fitted with electronic components, particularly to a key fitted with a self-contained memory unit in the key head, with one wire bus connection to a contact for connection to a lock or reader. As mentioned above, keys and cylinders employing other electronic or other non-mechanical features, as well as mechanical features, exist. In these existing types of systems, a keyholder will insert his/her key carrying electronic circuitry with contact means into the key receiving cylinder employing a matching contact means and, upon this insertion and sometimes insertion and turning, a contact will be made with the reader unit transferring the access information into the lock's decision making unit. This decision making unit is usually housed within the lock's trim plate. Upon the decision to grant access, the unit will electrically unlock the locking mechanism or allow the key to turn and retract the latch bolt of the lock.
These systems employ complicated and expensive circuitry and contact means, thus requiring special manufacturing of both cylinder and key.
The objective of the current invention is to provide a simple method of conversion that applies to any mechanical key and cylinder combination for their use in electronic access control systems; and to the mechanical key itself, efficiently fitted with a memory cell in a standardized Dallas Semiconductor can-like container, and this can be more than a memory cell and may include microprocessor, battery, read/write memory, etc.
A simplified approach is taken to the reader and the key connection by the present invention described below. In a preferred embodiment, the existing lock cylinders and keys are simply modified (or the same type of lock and key are OEM fitted) to become a part of an electronic access control lock while still maintaining their mechanically operating status. In the case of the key itself, it can take several forms as to the contact for the one wire bus connection, but in each case the key has a memory cell of the type described, fitted into the key head.